The 26-year-old New South Wales and Australian centre says it's one of the most difficult decisions he's ever had to make. The deal, believed to be worth about $600,000 a season, makes King one of the highest paid players in rugby league.

Storm chief executive Brian Waldron says it was impossible for the club to keep King, who had a year to run on his contract but had a get-out clause.

The popular King will play out the season with the Storm and coach Craig Bellamy says his team mates will be especially keen to farewell him with a premiership.